Landing On Snow...

[screaming_emu]

Freezing rain will ground us / stop us landing in most cases.

one way or another

[thecloudbuster]

There are two real issues with runways, the first is braking action, i.e. how slippy is it, and secondly contamination type / percentage as this will effect acceleration and possibly stopping to. Special performance tables are used, or some airlines have access to computer generated performance figures based on a various data inputs.

Operated into Kittila way up in northern Finland a few years ago with temps of -30C. The runway was covered in compacted snow. Essentially the landing technique is still the same, however the key is to ensure the performance data is correct. Peripheral vision can be effected if all the ground is white, and their are special techniques for "white out" landings. Air density corrections for altitude correction are important when it is very cold!!!

Slushy conditions can be the worst as it sticks to everything, gear, flaps etc. and seriously effects takeoff performance, although blowing snow can fuzz out the runway edges.

Freezing rain will ground us / stop us landing in most cases.

[a78jumper]

Actually, if the snow is too deep, you can't land because the gear will fail. The guys at the Durango FBO were telling me that back in the '80s a Metroliner got a bad snow report (told 1/4th inch when actually 4 inches), when the nosewheel touched down, the force from plowing through the snow caused it to snap off.

Sounds similar to a CF 5 of the Canadian Forces that made a landing at Westover ARB, MA about 25 years ago on a newly ploughed runway. Great except the operator left a six inch ridge of wet snow, which caused the nosewheel to collapse when the aircraft hit it. Consequences-a badly injured pilot and a written off aircraft.

[uy707]

Too bad I don't know some former Air Alpes and TAT captains and F/Os who used to fly to routes linking Orly to Courchevel, in the midst of the Alps. For over two decades or so, flights were operated with standard wheeled Twotters and during the spring seasons when loads are high, a dry leased Tyrolean Dash 7 supplemented/took over from the Twin Otters. Operating costs and fare charged eventually killed the service.
Should I would have got some acquaintances, I would have asked them to provide for infos.
Alain

[AJ]

Our Flying Manual has a whole 64 page section on 'Landing on Slippery or Contaminated Runways'.

Here are a few points from the recommended landing procedure:
Positive touchdown on speed. When nose down, spoliers up and tracking established smoothly and symmetrically apply moderate to firm application up to maximum braking if required, releasing the brakes if a lateral skid develops. Autobrake should be used where possible. Reverse thrust and aerodynamic drag will provide 80% of the high speed stopping force. Reverse should be returned to idle if a lateral skid develops. Expect a landing distance 40% longer than on a dry runway.

[LRJet Guy]

Takeoff is pretty much the same in reverse. The rudder becomes effective at 60 kts or less in most airplanes, and it takes little time to get to that speed. You use differential power before the rudder becomes effective to keep 'er going straight.

Differential power is VERY effective in maintaining directional control. Most Beech 1900's aren't even equipped with nosewheel steering. Differental power and brakes only. The nosewheel steering in the Dash is MEL-able, meaning we have to use differential power when its broken.

Multiengine tailwheel airplanes use it too. No steering there.

[pbateson]

What about takeoff?

[bbuse]

As for snow, I have landed on some snowy patches, it can make for an interesting landing, but as Joe said, use what you have properly you can manage it or save yourself from something horrible.

I have been on a number of airline flights where we landed on runways with patches of snow and it didn't seem to be a problem. The only difference was that the touchdown tended to be more firm, which I believe is a proper technique for the conditions.

[LRJet Guy]

Anti skid helps out a lot. We take a pretty big weight penalty if it is inop.

[Mungous]

Well over here the airports just work pretty hard to keep the runway clear as best they can or cancel all flights - but then we don't get torrential snow like some of you guys do

[chrisburns]

Tell that to Southwest...

I was going to say....

As for snow, I have landed on some snowy patches, it can make for an interesting landing, but as Joe said, use what you have properly you can manage it or save yourself from something horrible.

[screaming_emu]

Never landed on snow, but I have hit a couple icy patches. Just use your flight controls (ailerons, rudder) to keep control as long as possible. None of the planes I have flown have anti-skid systems, I'm sure that helps considerably.

[LRJet Guy]

Landing in snow isn't too bad, it's the taxiing that'll get you. You just make sure you never let the airplane go anywhere you don't want it. You also have to remember that the brakes don't work too well on snow, and to keep the speed down. On the rollout, the rudder stays effective for a long time, so you keep good directional control until you get slow.

One of the things you don't have in a car that you do have in an airplane for control is differential thrust. It helps out a lot.

[Foxtrot]

Re:

Which why I said "usually." Besides, we all know the facts about that case, and it's an oddity, not the usual.

Foxtrot

[E-Diddy!]

Pilots usually don't operate planes in blizzard conditions.

Foxtrot

Tell that to Southwest...